sugar manufacture by Dr Vijaya Shastry

1. A Presentation

2. Sugar Industry
 Introduction.
 History of Sugar.
 Sugar Manufacturing Process.

3. History of Sugar
• It is thought that cane sugar was first used by man in
Polynesia from where it spread to India.
• In 510 BC the Emperor Darius of what was then Persia
invaded India where he found "the reed which gives honey
without bees“.
• It was the major expansion of the Arab peoples in the
seventh century AD that led to a breaking of the secret.
When they invaded Persia in 642 AD they found sugar
cane being grown and learnt how sugar was made.
• Sugar was only discovered by western Europeans as a
result of the Crusades in the 11th Century AD.
• In the 15th century AD, European
sugar was refined in Venice.

4. What is Sugar?
What we call sugar, the chemist knows as
'sucrose', in the grouping called carbohydrates.
The simplest of the sugars is glucose, C6H12O6
Sucrose, C12H22O11, is a condensation molecule
made up of two glucose molecules [less a water
molecule to make the chemistry work].

5. How Sugar is formulated?
 The process whereby plants make sugars is photosynthesis. The plant
takes in carbon dioxide from the air though pores in its leaves and
absorbs water through its roots. These are combined to make sugar
using energy from the sun and with the help of a substance called
chlorophyll. Chlorophyll is green which allows it to absorb the sun's
energy more readily and which, of course, gives the plants' leaves their
green color. The reaction of photosynthesis can be written as the
following chemical equation when sucrose is being made:
12 CO2 + 11 H2 O = C12 H22 O11 + 12 O2
carbon dioxide + water = sucrose + oxygen

6. Statistics
Sugar is produced in 121 Countries.
Global production now exceeds 120 Million tons a
year.
Per Capita annual consumption is 30 – 46 kg.
Approximately 70% is produced from sugar cane.
The remaining 30% is produced from sugar beet.

7. By-Product Of Sugar Cane
Bagasse:
It is produced in the mill house in a quantity of about
30% of the crushed cane.
The bagasse contains 50% moisture
It is used as a fuel for boilers (processing stage).
Bagasse is also used for chip-board and paper
manufacture.

8. Molasses:
Molasses is a common ingredient in
baking, often used in baked goods such
as ginger bread cookies.
 80% of total available molasses is
exported

9. Ethanol:
The sugar sector has the capacity to produce
over 2.5 million metric tons (MMT) of
molasses available for processing into ethanol.
sugar industry produces more than half a
million tons of ethanol per annum from cane
molasses, over 50 per cent of which is
exported at an average price of about
$500/MT. Main destinations include: Europe,
Far Eastern (Korea, Japan, Taiwan and the
Philippines) and Middle East (Dubai and
Saudi Arabia).

10. History of Sugar
• It is thought that cane sugar was first used by man in
Polynesia from where it spread to India.
• In 510 BC the Emperor Darius of what was then Persia
invaded India where he found "the reed which gives honey
without bees“.
• It was the major expansion of the Arab peoples in the
seventh century AD that led to a breaking of the secret.
When they invaded Persia in 642 AD they found sugar
cane being grown and learnt how sugar was made.
• Sugar was only discovered by western Europeans as a
result of the Crusades in the 11th Century AD.
• In the 15th century AD, European
sugar was refined in Venice.

11. Sugar Manufacturing Process
1. Growing & Harvesting the Cane
2. Cane preparation for Milling
3. Milling
4. Clarification
5. Evaporation
6. Crystallization
7. Centrifugation
8. Drying
9. Refining

12. Manufacturing Process and
Technology

Sugar (sucrose) is a carbohydrate that occurs naturally in every fruit and
vegetable. It is a major product of photosynthesis, the process by which plants
transform the sun's energy into food. Sugar occurs in greatest quantities in
sugarcane and sugar beets from which it is separated for commercial use. The
natural sugar stored in the cane stalk or beet root is separated from rest of the
plant material through a process known as refining.

For sugarcane, the process of refining is carried out in following steps
 Pressing of sugarcane to extract the juice.
 Boiling the juice until it begins to thicken and sugar begins to crystallize.
 Spinning the crystals in a centrifuge to remove the syrup, producing raw
sugar.
 Shipping the raw sugar to a refinery where it is washed and filtered to remove
remaining non-sugar ingredients and color.
 Crystallizing, drying and packaging the refined sugar

13.  Beet sugar processing is similar, but it is done in one continuous process without the raw sugar
stage. The sugar beets are washed, sliced and soaked in hot water to separate the sugar -containing
juice from the beet fiber. The sugar-laden juice is then purified, filtered, concentrated and dried in a
series of steps similar to cane sugar processing.
 For the sugar industry, capacity utilization is conceptually different from that applicable to
industries in general. It depends on three crucial factors the actual number of ton of sugarcane
crushed in a day, the recovery rate which generally depends on the quality of the cane and actual
length of the crushing season.

Since cane is not transported to any great extent, the quality of the cane that a factory receives
depends on its location and is outside its control. The length of the crushing season also depends
upon location with the maximum being in south India.
Sugarcane in India is used to make either sugar, khandsari or gur. However, sugar products
produced worldwide are divided into four basic categories : granulated, brown, liquid sugar and
invert sugar.
 Granulated : Granulated sugar is the pure crystalline sucrose. It can be classified into seven types of
sugar based on the crystal size. Most of these are used only by food processors and professional
bakers. Each crystal size provides unique functional characteristics that make the sugar appropriate
for the food processor's special need.

14. Sugar Beet
Sugar beet is a temperate climate biennial root crop.
It produces sugar during the first year of growth in order
to see it over the winter and then flowers and seeds in the second year.
It is therefore sown in spring and harvested in the first autumn/early winter.
As for sugar cane, there are many cultivars available to the beet farmer.
The beet stores the sucrose in the bulbous root which
bears a strong resemblance to a fat parsnip.
A typical sugar content for mature beets is 17% by weight but the value depends on
the variety
and it does vary from year to year and location to location.
This is substantially more than the sucrose content of mature cane
but the yields of beet per hectare are much lower than for cane
so that the expected sugar production is only about 7 tons per hectare.

17. The processes in this industry are
 Cane Shredding
 The cane is broken/cut into small pieces to enable easier movement through the milling machine.
 Milling
 The shredded cane is passed through rollers which crush them to extract cane juice. [Similar to the
cane juice extracted by the vendors who sell you sugar cane juice.]
 Heating and Adding lime
 The extracted juice is then heated to make it a concentrate and lime is added to the heated juice.
 Clarification
 Muddy substance is removed from the concentrate through this process
 Evaporation
 Water is removed from the juice by evaporation.
 Crystallisation and Separation
 Sugar crystals are grown from the dry juice concentrate in this process.
 Spinning
 Molasses are separated from sugar using Centrifugals in this process.
 Drying
 Sugar is obtained by drying the wet raw sugar obtained in the spinning process.

18. How is sugar processed?
The initial stage involves sampling, weighing and
washing the sugarcane. From there the material
passes to can crushers and then into the mill. The
bagasse, which results from the milling, is used in the
boilers for steam production that is used to power the
process. The surplus bagasse from this stage is used in
industry

21. Harvesting

Sugar cane is harvested by chopping down the stems
but leaving the roots so that it re-grows in time for
the next crop. Harvest times tend to be during the dry
season and the length of the harvest ranges from as
little as 2 ½ months up to 11 months.

23. Extraction

The first stage of processing is the extraction of the
cane juice. In many factories the cane is crushed in a
series of large roller mills: similar to a mangle
[wringer] which was used to squeeze the water out of
clean washing a century ago. The sweet juice comes
gushing out and the cane fibre is carried away for use
in the boilers. In other factories a diffuser is used as is
described for beet sugar manufacture. Either way the
juice is pretty dirty: the soil from the fields, some
small fibres and the green extracts from the plant are
all mixed in with the sugar.

25. Clarification

The extracted cane juice is pH tested and adjusted
with lime before it is heated and sent to large
clarifying tanks. These tanks
allow for the settling of solids to the bottom leaving
only clear juice to continue through the process.

27. Evaporation

The factory can clean up the juice quite easily with
slaked lime (a relative of chalk) which settles out a lot
of the dirt so that it can be sent back to the fields.
Once this is done, the juice is thickened up into a
syrup by boiling off the water using steam in a process
called evaporation. Sometimes the syrup is cleaned up
again but more often it just goes on to the crystal-
making step without any more cleaning. The
evaporation is undertaken in order to improve the
energy efficiency of the factory.

29. Boiling

The syrup is placed into a very large pan for boiling.
In the pan even more water is boiled off until
conditions are right for sugar crystals to grow.

31. Crystallisation

The heated syrup begins to crystallize and separates
into sugar crystals and molasses called "massecuite."
The crystallizers cool the mixture of sugar crystals
and molasses which causes the crystals to grow in
size.You may have done something like this at school
but probably not with sugar because it is difficult to
get the crystals to grow well. In the factory the
workers usually have to throw in some sugar dust to
initiate crystal formation.

33. Centrifugation

To remove the sugar crystals from the molasses, high-speed
rotating centrifugals spin off the molasses leaving only the raw
sugar crystals on the centrifugal screens. The remaining product
is blackstrap molasses which is then stored in tanks and later
sold as cattle feed. After all of the commercially recoverable raw
sugar is produced it is transferred into huge warehouses for
storage until It is ready to be transported to refineries.
Sugar processing is a highly specialized, computer-controlled,
technical process that requires a combination of sensitive
machinery and experienced individuals to succeed.
Approximately one ton of sugarcane is required to produce 220
pounds of raw sugar. We at Sugar Cane Growers Cooperative of
Florida are proud of our facilities and the people who run them.

35. Storage

The final raw sugar forms a sticky brown mountain in
the store and looks rather like the soft brown sugar
found in domestic kitchens. It could be used like that
but usually it gets dirty in storage and has a
distinctive taste which most people don't want. That
is why it is refined when it gets to the country where
it will be used. Additionally, because one cannot get
all the sugar out of the juice, there is a sweet by-
product made: molasses. This is usually turned into a
cattle food or is sent to a distillery where alcohol is
made.

37. Power

So what happened to all that fibre from crushing the sugar cane? It is called
"bagasse" in the industry. The factory needs electricity and steam to run, both
of which are generated using this fibre.
The bagasse is burnt in large furnaces where a lot of heat is given out which
can be used in turn to boil water and make high pressure steam. The steam is
then used to drive a turbine in order to make electricity and create low
pressure steam for the sugar making process. This is the same process that
makes most of our electricity but there are several important differences.
When a large power station produces electricity it burns a fossil fuel [once
used, a fuel that cannot be replaced] which contaminates the atmosphere and
the station has to dump a lot of low grade heat. All this contributes to global
warming. In the cane sugar factory the bagasse fuel is renewable and the gases
it produces, essentially CO2, are more than used up by the new cane growing.
Add to that the factory use of low grade heat [a system called co-generation]
and one can see that a well run cane sugar estate is environmentally friendly.

39. Uses of Sugar
 Sugar is used for many purposes in the food industry. It is vital in maintaining
the safety and availability of our food.
 Ice cream is made thicker and smoother with sugar. More than 20% of ice
cream is sugar.
 Sugar helps cakes to be moist and soft, and to stay fresh longer.
 Soft drinks and fruit juice are often 10% or 12% sugar. As well as adding
flavour, the sugar makes the drinks heavier and more pleasant to drink.
 The sugar in jams helps them to keep for a longer time, by stopping mould
and germs from growing.
 Natural sugar in canned fruit also acts as a preservative in the same way.
 Condensed milk relies on up to 55% sugar content.
 Cane sugar is used in making many lollies.
 Sugar is used to bring out the flavours of other foods such as preserved meats,
tomato sauce and canned soup.
 Custard is made smooth and creamy as well as sweet by sugar.
 Many medicines have sugar added to hide their bitter taste. Some cough
syrups have sugar to make them more soothing

40. THANKS
Email me
vijayarjc@gmail.com
Mobile Phone
9819794779
Asst Prof, Physical Chemistry, RJ College
Ghatkopar,Mumbai, India